Fuel combustion furnace



May 22, 1951 w. B. LEVIS FUEL COMBUSTION FURNACE Filed March 2, 1948 2Sheets-Sheet 1 .NVENTOR MQQN May 22, 1951 w. B. LEVIS FUEL COMBUSTIONFURNACE 2 Sheets-Sheet 2 Filed March 2, 1948 Patented May 22, 1951UNITED STATES PATENT OFFICE 2,553,713 FUEL consusmn FifaNAoE William B.Levis, rhiaaapta, Pa. Application March 2, 1948, Serial No. 12,532

v 3 Claims. 1

My invention relates to 'a fuel combustion furnace.

A purpose of my invention is to simplify the fabrication and increasethe durability of fuel combustion furnaces.

, A further purpose is to provide a baflle type fuel'combustion furnacein which the heat trans- ;fer tubes extend immediately below the'baifles,

and the ba'files preferably conform to the curvature of the tube bends.

A further purpose is to support the heat transfer tubes from thebaffles, preferably by an interlock between the same.

A further purpose is to provide a perforated flange having locking earson the baffles for support of the heat transfer tubes.

Further purposes appear in the specification and in the claims. In thedrawings I have chosen to illustrate a lfewonlyo'f the numerousembodiments in which my invention may appear, choosing the forms shownfrom the standpoints of convenience in illustration, satisfactoryoperation and clear demonstratio'n of the principles involved.

Figure 1 isa verticalsection across a fuel'combustion furnace conformingto my invention.

Figure 2 'is a fragmentary perspective of the headers, heat transfertubes and baffles, showing a minor variation in one baffle, I v

Figure -3 is a fragmentary perspective of the baffie flanges showing theperforations and looking ears before the heat "transfer tubes have beenapplied.

Figure 4 is a sectional perspective of the structure'of 'Fig'ure B'after'the heat transfer tubes hate'been applied.

In the drawings like numerals refer to like parts.

Describing "in 'i'llustration'but not in limitationand referring to thedrawings:

The -';present invention is concerned with fuel combustion furnaces ofthe type likely to be used as domestic heating furnaces, commonly knownas hot water heaters or furnaces. The invention may be applied to theheating of other media, as for example to the generation and heating ofsteam.

The furnace of the invention has side walls 2| suitably consisting of aninner metallic housing 22, an outer metallic housing 23 and intermediateheat insulation 24, as well as a roof 25 similarly constructed. Thefurnace rests on a base 26. At the bottom is positioned a combustionchamber 21 which in some cases has a roof 28 and a water jacket 28 andis provided with a burner 29, intended to indicate any conventional typefor introducing fuel and air, which might be oil, gas, pulverized coal,solid coal, or coke (using suitable fire bed supports not shown in thecase of solid fuel). From the firebox a flue opening 36 extends upwardlyinto a heat transferflue 3| occupying the entire upper portion of thefurnace, and terminating in a stack 32 at the top.

The heat transfer flue 3! is of serpentine contour due to the presenceof bafiies 33 alternately extending from opposite side walls part onlyof the distance across to the wall opposite each cur-ved'at39 to aid infollowing the bend of heat transfer pipes to be described, and in Figure-1 the downward bend on one baflle is reversed at 39' to guide thegases. This is optional and is. omitted in Figure 2. i V

Suitably-positioned adjacent the top and bottom of the flue are a hotwater header 40 for connection to thehot water heating system and :acool water header 4! for connection to the cool water return from theheating system, or

to a cold water inlet. The water back 23', if

used, 'is suitably connected to the header 4! by "a pipe ll, and hasinlet at H Connecting:

into each header and arranged side by side are serpentine bend heattransfer pipes 42, prefer :'a;b'ly "of copper, brass or bronze for goodheat conductivity, .and having individual reverse bend portions 43 whichconform to the bottoms of individual bafiles. It will be understood thatthe she'lfportions of the 'bafiies preferably upwardly slope at 44 fromtheir origins to their outer edges, and that the reverse bend portions43 of the pipes conform and preferably are substantially in contact withthe under sides of the baffles along the shelf portions and along thedownwardly bent portions 39. This aids in defleeting gases and inmetallic conduction of heat from the bafiles to the heat transfer pipesin contact therewith.

In many prior constructions the gases at the reversals of serpentinebends have been carried far away from the heat transfer pipes, but thiscannot be true in the present construction, since outer edge ofsuccessive bafiies.

3 the gases at each serpentine bend in the flue must flow between thepipes at 45 and then are compelled by the baflies to follow thecurvature of the bends of the pipes by the next baflle above.

The bottom baflie 46 normally will not have this downwardly curvedportion 39 and the top baiiie 4'1 will conveniently comprise only thedownwardly bent portion, since the furnace roof will perform much of thefunction of the shelf portion.

One of the problems in the prior art has been the tendency of the heattransfer tubes to sag or deform because of inadequate support. At theouter ends of several baffles I provide suitably downwardly directedflanges 48 having perforations 49 in the paths of the heat transferpipes and severed at the middle of each perforaasssms tion to the edgeof the flange at 50 to provide retaining ears 5i.

To support the heat transfer pipes the retaining ears in pairs are bentrespectively backward and forward between each two perforations as shownat 52 in Figure 3, using pliers or the like, after which the pipes 82are inserted in the perforations and the ears bent back to their normalpositions as shown at 53 in Figure l. The completed result is shown inFigure 4. This bending is possible as the baflles will be made of sheetsteel, copper or the like. Thus the flanges serve to lock and supporteach heat transfer pipe at the v The attachment is extremely convenientas it merely involves bending the ears on the perforations back andforth.

In operation the device of the invention can conveniently be assembledby uniting the heat transfer pipes in the headers as by welding orspreading the ends of the pipes, then applying the baffles to the pipesby bending the ears on the bailie flanges, then assembling the pipes insuitable pipe channels 54 and 55 through the inner walls of the furnace,then uniting the baflles to the end walls and finally assembling theend. Compared to the assembly time usually required, a marked reductionin assembly time is accom plished by the present invention.

The furnace of the invention will function in an improved manner due tothe close contact between the heat transfer tubes and the under surfacesof the walls of the baffles, with at the same time allowance of adequatelateral spacing between the pipes to permit flow of flue gas between thepipes at the ends of the baffles.

In view of my invention and disclosure variations and modifications tomeet individual whim or particular need will doubtless become evident toothers skilled in the art, to obtain all or part of the benefits of myinvention without copying the structure shown, and I, therefore, claimall such insofar as they fall within the reasonable spirit and scope ofmy claims.

Having thus described my invention what I 0 Number 4 claim as new anddesire to secure by Letters Patent is:

1. In a fuel combustion furnace, at flue having flue walls, a pluralityof baffles supported from the flue walls one above another, each bafileextending from one side of the flue part only of the distance to theopposite wall of the flue and each alternate bafile extending from theopposite wall to form a serpentine flue passage, headers at the top andbottom of the flue, serpentine heat transfer pipes extending side byside through the flue, connected at the top and bottom to the headersand individual bends of the pipes extending along the bottoms ofindividual baflles, and flanges on the baffles having openings throughthe flanges through which the pipes pass to interconnect the'pipes withthe bafiies.

2. In afuel combustion furnace, a flue having flue walls, a plurality ofbaiiies supported from the flue walls and extendingfro-m one side of theflue part only of the distance to the opposite side, the alternatebaffles extending from opposite sides, and individual bafies beingdownwardly curved across their lengths adjoining the side from whichthey extend, top and bottom headers, serpentine pipes extending throughthe flue between the bafiles, connected at their ends to the headers andfollowing the curvature and shape of the under pcrtions of the bailies,the curvature of the pipes following the curvature of the bailles at thesides from whichthe bafiles extend and flanges on the baffles havinginterconnecting openings through which the pipes pass.

3. In a fuel combustion furnace, a flue having flue walls, a pluralityof superimposed bafiies supported from the flue walls and extendingalternately from opposite sides of the flue part only of the distanceacross the flue so as toproduce a serpentine path, each baflie having atits outer end a downwardly directed perforated flange having integrallocking ears, and serpentine pipes extending through the flue below theindividual baffles and through the perforations of the flanges, beinglocked therein by the ears to support the pipes from the baffles.

WILLIAM B. LEVIS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Gunckel June 8, 1915 Duffy Apr. 4, 1922Kuhner et a1 Apr. 29, 1941 Beers July 22, 1941 FOREIGN PATENTS CountryDate Switzerland Mar. 16, 1934 Number

